For the Fetch Quests, keep an eye on the Tavern News.
Look out for:
Fetch_Shipyard_title {#stown# is expanding the warfleet}
Fetch_Shipyard_entry {The governor of #stown# has ordered the shipyard to create new ships for the warfleet. This will require a lot of resources so chances are some of these are depleted.}
Fetch_Tailor_title {#stown# is expanding the military}
Fetch_Tailor_entry {The fortcommander of #stown# is drafting new people to join their army. This will provide the tailor with a lot of new work and might deplete some of the resources of the island.}
Fetch_Smith_title {#stown# wants new weapons}
Fetch_Smith_entry {To fight better the governor of #stown# has decided that all weapons should be checked and improved. This will probably make the smith use a lot of resources and they might need some help.}
When I was testing last month, I did get the Shipyard one, which triggered and worked fine.
The skill-increase from items should be no different from before. I don't recall any related code being touched.
Note that not all item skill modifiers are actually visible in the Inventory screen on Realistic Game Mode.
More specifically, Jewels, Indian Artefacts and Minerals DO increase your skills in Realistic Game Mode, but this is hidden by default.
This to make the "superstition" elements of this more believable. Only high-level books are obvious about their skill effects.
Treasure Quests are 100% random. That means you could randomly get the same one very frequently.
There is no relation to previous Treasure Quests at all.
The destination for Trade Quests depends on your national relations and those of the other nations involved.
You won't get any Trade Quests for towns that are enemy to the trader's nation and/or yourself.
You don't need to do Ship Hunting to gain points with a nation.
Just get a LoM and start attacking their enemies at random. That'll work.